Prefer clang++
Fix fatal clang error due to ERR_get_error returning unsigned
Require C++11
Update bdlib for C++11 usage
Merge branch 'clang-c++11-bdlib' into next

* clang-c++11-bdlib:
  Update bdlib for C++11 usage
  Require C++11
  Fix fatal clang error due to ERR_get_error returning unsigned
  Prefer clang++